[{"language":[{"iso":"eng"}],"keyword":["Densification","set-recovery","swelling and shrinkage"],"date_created":"2024-07-27T05:38:16Z","publication":"Wood Material Science & Engineering","publication_identifier":{"eissn":["1748-0280"],"issn":["1748-0272"]},"date_updated":"2025-06-25T13:03:03Z","author":[{"last_name":"Kölli","first_name":"Nathan","full_name":"Kölli, Nathan","id":"74242"},{"full_name":"Frühwald-König, Katja","last_name":"Frühwald-König","first_name":"Katja","id":"26232"},{"full_name":"Hackel, Martin","first_name":"Martin","id":"79798","last_name":"Hackel"}],"year":"2024","external_id":{"isi":["001274838600001"]},"page":"1-12","status":"public","title":"Hygroscopic behavior of thermo-hygro-mechanical (THM) densified oil palm sawn timber","citation":{"ieee":"N. Kölli, K. Frühwald-König, and M. Hackel, “Hygroscopic behavior of thermo-hygro-mechanical (THM) densified oil palm sawn timber,” <i>Wood Material Science &#38; Engineering</i>, pp. 1–12, 2024, doi: <a href=\"https://doi.org/10.1080/17480272.2024.2381100\">10.1080/17480272.2024.2381100</a>.","ama":"Kölli N, Frühwald-König K, Hackel M. Hygroscopic behavior of thermo-hygro-mechanical (THM) densified oil palm sawn timber. <i>Wood Material Science &#38; Engineering</i>. Published online 2024:1-12. doi:<a href=\"https://doi.org/10.1080/17480272.2024.2381100\">10.1080/17480272.2024.2381100</a>","chicago-de":"Kölli, Nathan, Katja Frühwald-König und Martin Hackel. 2024. Hygroscopic behavior of thermo-hygro-mechanical (THM) densified oil palm sawn timber. <i>Wood Material Science &#38; Engineering</i>: 1–12. doi:<a href=\"https://doi.org/10.1080/17480272.2024.2381100\">10.1080/17480272.2024.2381100</a>, .","din1505-2-1":"<span style=\"font-variant:small-caps;\">Kölli, Nathan</span> ; <span style=\"font-variant:small-caps;\">Frühwald-König, Katja</span> ; <span style=\"font-variant:small-caps;\">Hackel, Martin</span>: Hygroscopic behavior of thermo-hygro-mechanical (THM) densified oil palm sawn timber. In: <i>Wood Material Science &#38; Engineering</i>. London, Taylor &#38; Francis (2024), S. 1–12","short":"N. Kölli, K. Frühwald-König, M. Hackel, Wood Material Science &#38; Engineering (2024) 1–12.","chicago":"Kölli, Nathan, Katja Frühwald-König, and Martin Hackel. “Hygroscopic Behavior of Thermo-Hygro-Mechanical (THM) Densified Oil Palm Sawn Timber.” <i>Wood Material Science &#38; Engineering</i>, 2024, 1–12. <a href=\"https://doi.org/10.1080/17480272.2024.2381100\">https://doi.org/10.1080/17480272.2024.2381100</a>.","apa":"Kölli, N., Frühwald-König, K., &#38; Hackel, M. (2024). Hygroscopic behavior of thermo-hygro-mechanical (THM) densified oil palm sawn timber. <i>Wood Material Science &#38; Engineering</i>, 1–12. <a href=\"https://doi.org/10.1080/17480272.2024.2381100\">https://doi.org/10.1080/17480272.2024.2381100</a>","ufg":"<b>Kölli, Nathan/Frühwald-König, Katja/Hackel, Martin</b>: Hygroscopic behavior of thermo-hygro-mechanical (THM) densified oil palm sawn timber, in: <i>Wood Material Science &#38; Engineering</i> (2024),  S. 1–12.","havard":"N. Kölli, K. Frühwald-König, M. Hackel, Hygroscopic behavior of thermo-hygro-mechanical (THM) densified oil palm sawn timber, Wood Material Science &#38; Engineering. (2024) 1–12.","bjps":"<b>Kölli N, Frühwald-König K and Hackel M</b> (2024) Hygroscopic Behavior of Thermo-Hygro-Mechanical (THM) Densified Oil Palm Sawn Timber. <i>Wood Material Science &#38; Engineering</i> 1–12.","mla":"Kölli, Nathan, et al. “Hygroscopic Behavior of Thermo-Hygro-Mechanical (THM) Densified Oil Palm Sawn Timber.” <i>Wood Material Science &#38; Engineering</i>, 2024, pp. 1–12, <a href=\"https://doi.org/10.1080/17480272.2024.2381100\">https://doi.org/10.1080/17480272.2024.2381100</a>.","van":"Kölli N, Frühwald-König K, Hackel M. Hygroscopic behavior of thermo-hygro-mechanical (THM) densified oil palm sawn timber. Wood Material Science &#38; Engineering. 2024;1–12."},"place":"London","doi":"10.1080/17480272.2024.2381100","_id":"11792","type":"scientific_journal_article","user_id":"83781","department":[{"_id":"DEP7018"},{"_id":"DEP1309"}],"abstract":[{"lang":"eng","text":"To facilitate the drying process and enhance the properties of oil palm wood, oil palm boards were mechanically pre-dewatered and thermo-hygro-mechanically (THM) densified. The thickness of the boards was reduced with compression ratios of 40%, 60% and 75%. Since densified wood tends to recover from compression, especially under humid conditions, this study examined the set-recovery and the hygroscopic behavior of THM densified oil palm wood. The equilibrium moisture content (EMC), differential swelling and swelling coefficient, linear swelling and shrinkage as well as the differential swelling anisotropy were determined under climate conditions with different relative humidity (RH) (20°C/35% RH, 20°C/65% RH and 20°C/85% RH). The maximum swelling was measured after water soaking and the remaining set-recovery was evaluated after re-drying at 103°C. The EMC was reduced by the THM process by around 20%. In the direction of compression (thickness), the densified specimens show higher values for all analyzed swelling and shrinkage parameters than the undensified specimens from the equivalent position within the trunk. The maximum swelling in thickness of 22–38% during water soaking is mostly reversed by shrinkage during re-drying and a comparably low remaining set-recovery of 3–8% is measured at oven dry condition."}],"quality_controlled":"1","publisher":"Taylor & Francis","isi":"1","publication_status":"published"},{"publication":"Wood material science and engineering ","publication_identifier":{"issn":["1748-0272"],"eissn":["1748-0280"]},"date_created":"2024-02-25T07:32:31Z","date_updated":"2025-06-25T12:42:37Z","keyword":["Bending strength","densification","e-modulus","g-modulus","shear strength"],"language":[{"iso":"eng"}],"title":"Elasto-mechanical properties of thermo-hygro-mechanical (THM) densified oil palm sawn timber","citation":{"chicago-de":"Kölli, Nathan und Katja Frühwald-König. 2024. Elasto-mechanical properties of thermo-hygro-mechanical (THM) densified oil palm sawn timber. <i>Wood material science and engineering </i>: 1–18. doi:<a href=\"https://doi.org/10.1080/17480272.2024.2317977\">10.1080/17480272.2024.2317977</a>, .","din1505-2-1":"<span style=\"font-variant:small-caps;\">Kölli, Nathan</span> ; <span style=\"font-variant:small-caps;\">Frühwald-König, Katja</span>: Elasto-mechanical properties of thermo-hygro-mechanical (THM) densified oil palm sawn timber. In: <i>Wood material science and engineering </i>. London, Taylor &#38; Francis (2024), S. 1–18","short":"N. Kölli, K. Frühwald-König, Wood Material Science and Engineering  (2024) 1–18.","chicago":"Kölli, Nathan, and Katja Frühwald-König. “Elasto-Mechanical Properties of Thermo-Hygro-Mechanical (THM) Densified Oil Palm Sawn Timber.” <i>Wood Material Science and Engineering </i>, 2024, 1–18. <a href=\"https://doi.org/10.1080/17480272.2024.2317977\">https://doi.org/10.1080/17480272.2024.2317977</a>.","apa":"Kölli, N., &#38; Frühwald-König, K. (2024). Elasto-mechanical properties of thermo-hygro-mechanical (THM) densified oil palm sawn timber. <i>Wood Material Science and Engineering </i>, 1–18. <a href=\"https://doi.org/10.1080/17480272.2024.2317977\">https://doi.org/10.1080/17480272.2024.2317977</a>","havard":"N. Kölli, K. Frühwald-König, Elasto-mechanical properties of thermo-hygro-mechanical (THM) densified oil palm sawn timber, Wood Material Science and Engineering . (2024) 1–18.","bjps":"<b>Kölli N and Frühwald-König K</b> (2024) Elasto-Mechanical Properties of Thermo-Hygro-Mechanical (THM) Densified Oil Palm Sawn Timber. <i>Wood material science and engineering </i> 1–18.","mla":"Kölli, Nathan, and Katja Frühwald-König. “Elasto-Mechanical Properties of Thermo-Hygro-Mechanical (THM) Densified Oil Palm Sawn Timber.” <i>Wood Material Science and Engineering </i>, 2024, pp. 1–18, <a href=\"https://doi.org/10.1080/17480272.2024.2317977\">https://doi.org/10.1080/17480272.2024.2317977</a>.","ufg":"<b>Kölli, Nathan/Frühwald-König, Katja</b>: Elasto-mechanical properties of thermo-hygro-mechanical (THM) densified oil palm sawn timber, in: <i>Wood material science and engineering </i> (2024),  S. 1–18.","van":"Kölli N, Frühwald-König K. Elasto-mechanical properties of thermo-hygro-mechanical (THM) densified oil palm sawn timber. Wood material science and engineering . 2024;1–18.","ieee":"N. Kölli and K. Frühwald-König, “Elasto-mechanical properties of thermo-hygro-mechanical (THM) densified oil palm sawn timber,” <i>Wood material science and engineering </i>, pp. 1–18, 2024, doi: <a href=\"https://doi.org/10.1080/17480272.2024.2317977\">10.1080/17480272.2024.2317977</a>.","ama":"Kölli N, Frühwald-König K. Elasto-mechanical properties of thermo-hygro-mechanical (THM) densified oil palm sawn timber. <i>Wood material science and engineering </i>. Published online 2024:1-18. doi:<a href=\"https://doi.org/10.1080/17480272.2024.2317977\">10.1080/17480272.2024.2317977</a>"},"external_id":{"isi":["001170089500001"]},"year":"2024","author":[{"full_name":"Kölli, Nathan","first_name":"Nathan","last_name":"Kölli","id":"73742"},{"first_name":"Katja","full_name":"Frühwald-König, Katja","id":"26232","last_name":"Frühwald-König"}],"status":"public","page":"1-18","type":"scientific_journal_article","user_id":"83781","_id":"11114","doi":"10.1080/17480272.2024.2317977","place":"London","isi":"1","publication_status":"published","abstract":[{"text":"Oil palm wood is mainly low in density and since strength and stiffness correlate with density, this study aimed to enhance the properties of oil palm wood through thermo-hygro-mechanical (THM) densification. In contrast to other studies using small laboratory-sized specimens, this study examined the densification of oil palm boards in sawn timber dimensions of 2.0 m length. Modulus of elasticity (MOE) and modulus of rupture (MOR) in bending, shear strength and shear modulus parallel by two-plate shear test and Young’s modulus in the three main directions as well as shear modulus in the three planes by ultrasonic testing were determined at densified and undensified specimens. The bending properties were increased to considerably higher levels and a compression ratio of 60% showed higher MOE and MOR values than that of 40%; whereas for boards of the inner part of the trunk, a compression ratio of 60% showed better results than that of 75%. The shear properties were only slightly increased through densification. Densification can improve the properties of oil palm wood. However, the wide range of density and properties found in natural oil palm wood is also present in densified oil palm wood.","lang":"eng"}],"department":[{"_id":"DEP7018"},{"_id":"DEP1309"}],"publisher":"Taylor & Francis","quality_controlled":"1"},{"status":"public","abstract":[{"text":"Sustainable use of renewable raw materials is an important issue of policy and industry. Wood prices are rising because of increasing market demand while simultaneously forests are challenged through conservation issues, deforestation and hazards. The main reasons for deforestation are agriculture, infrastructure and wood harvesting. Oil palm plantations stock on former tropical forest land and cover some 25 Mio ha worldwide. They are replanted every 25 years due to reduced productivity. Using the available wooden trunk material of the cleared plantation not only makes sense in ecological terms but is also a big chance for economy and trade. Research over the last 30 years has led to several ideas in the use for products. The biggest challenge is the anatomical structure of palm wood which is different to coniferous or broadleaf trees. Hard vascular bundles are embedded in low-density parenchyma storage tissue with high moisture content. The soft and sponge-like parenchyma tissue can be compressed easily and a significant share of the water (mc up to 600 % based on dry wood) can be squeezed out. Through press drying, the volume of the parenchyma can be reduced and the wood density increases. Wood strength and stiffness are related to its density and can be improved by densification. TH OWL developed a four-step densification process for oil palm boards. Oil palm lumber was produced from oil palm trunks in a sawmill and then densified under defined conditions. The densification process includes (1) compression to remove a certain percentage of the palm sap, (2) plastification under heat and moisture to soften the wood, (3) hot compression to achieve the densification and remove more water, and (4) press-drying to dry and harden the material. A future perspective on how the laboratory tests could be scaled up to an industrial application with a possible machinery set-up is presented. ","lang":"eng"}],"department":[{"_id":"DEP7018"},{"_id":"DEP1309"}],"conference":{"location":"St. Simons Island, Georgia / USA","name":"PTF BPI 2021 (Process Technologies for the Forest & Biobased Product Industries)","end_date":"2021-11-03","start_date":"2021-11-01"},"year":"2021","author":[{"full_name":"Kölli, Nathan","last_name":"Kölli","id":"74242","first_name":"Nathan"}],"publication_status":"published","citation":{"short":"N. Kölli, in: T.M. Young , A. Petutschnigg (Eds.), 6th International Conference on  Process Technologies for the Forest  and Biobased Products Industries  PTF BPI 2021 , 2021.","din1505-2-1":"<span style=\"font-variant:small-caps;\">Kölli, Nathan</span>: Densification and Press-Drying of Wet Oil Palm Lumber. In: <span style=\"font-variant:small-caps;\">Young , T. M.</span> ; <span style=\"font-variant:small-caps;\">Petutschnigg, A.</span> (Hrsg.): <i>6th International Conference on  Process Technologies for the Forest  and Biobased Products Industries  PTF BPI 2021 </i>, 2021","chicago-de":"Kölli, Nathan. 2021. Densification and Press-Drying of Wet Oil Palm Lumber. In: <i>6th International Conference on  Process Technologies for the Forest  and Biobased Products Industries  PTF BPI 2021 </i>, hg. von Timothy M.  Young  und Alexander  Petutschnigg.","van":"Kölli N. Densification and Press-Drying of Wet Oil Palm Lumber. In: Young  TM, Petutschnigg A, editors. 6th International Conference on  Process Technologies for the Forest  and Biobased Products Industries  PTF BPI 2021 . 2021.","havard":"N. Kölli, Densification and Press-Drying of Wet Oil Palm Lumber, in: T.M. Young , A. Petutschnigg (Eds.), 6th International Conference on  Process Technologies for the Forest  and Biobased Products Industries  PTF BPI 2021 , 2021.","mla":"Kölli, Nathan. “Densification and Press-Drying of Wet Oil Palm Lumber.” <i>6th International Conference on  Process Technologies for the Forest  and Biobased Products Industries  PTF BPI 2021 </i>, edited by Timothy M.  Young  and Alexander  Petutschnigg, 2021.","bjps":"<b>Kölli N</b> (2021) Densification and Press-Drying of Wet Oil Palm Lumber. In Young  TM and Petutschnigg A (eds), <i>6th International Conference on  Process Technologies for the Forest  and Biobased Products Industries  PTF BPI 2021 </i>.","ufg":"<b>Kölli, Nathan</b>: Densification and Press-Drying of Wet Oil Palm Lumber, in: <i>Young , Timothy M./Petutschnigg, Alexander (Hgg.)</i>: 6th International Conference on  Process Technologies for the Forest  and Biobased Products Industries  PTF BPI 2021 , o. O. 2021.","apa":"Kölli, N. (2021). Densification and Press-Drying of Wet Oil Palm Lumber. In T. M. Young  &#38; A. Petutschnigg (Eds.), <i>6th International Conference on  Process Technologies for the Forest  and Biobased Products Industries  PTF BPI 2021 </i>.","chicago":"Kölli, Nathan. “Densification and Press-Drying of Wet Oil Palm Lumber.” In <i>6th International Conference on  Process Technologies for the Forest  and Biobased Products Industries  PTF BPI 2021 </i>, edited by Timothy M.  Young  and Alexander  Petutschnigg, 2021.","ama":"Kölli N. Densification and Press-Drying of Wet Oil Palm Lumber. In: Young  TM, Petutschnigg A, eds. <i>6th International Conference on  Process Technologies for the Forest  and Biobased Products Industries  PTF BPI 2021 </i>. ; 2021.","ieee":"N. Kölli, “Densification and Press-Drying of Wet Oil Palm Lumber,” in <i>6th International Conference on  Process Technologies for the Forest  and Biobased Products Industries  PTF BPI 2021 </i>, St. Simons Island, Georgia / USA, 2021."},"title":"Densification and Press-Drying of Wet Oil Palm Lumber","_id":"6945","language":[{"iso":"eng"}],"keyword":["Oil Palm Wood","Densification","Drying"],"editor":[{"last_name":"Young ","first_name":"Timothy M. ","full_name":"Young , Timothy M. "},{"last_name":"Petutschnigg","first_name":"Alexander ","full_name":"Petutschnigg, Alexander "}],"date_updated":"2023-10-30T15:20:10Z","user_id":"83781","type":"conference","date_created":"2022-01-06T11:43:06Z","publication":"6th International Conference on  Process Technologies for the Forest  and Biobased Products Industries  PTF BPI 2021 "}]